1. Field of the Invention
The present invention relates to a laminating device to stack and bond together a laminate film applied with a hot-melt adhesive and a sheet, and more particularly to improvements in a laminating device that thermally pressure-bonds a laminate film and a sheet together as they are conveyed and in a thermal pressure bonding and conveying device used in the laminating device.
2. Background Art
Conventional laminating devices are found, for example, in Japanese Patent No. 3779014 (Embodiment of Invention, FIG. 4 to FIG. 7) and Japanese Patent No. 2901228 (Embodiment, FIG. 3).
Japanese Patent No. 3779014 discloses a laminating device which has a heating source to heat a laminate film, a pair of pressure-bonding rollers to bond the heated laminate film and a sheet material together and sensors to detect a temperature of the heating source and a temperature of the laminate film, and which controls the temperature of the heating source based on the sensor output.
Japanese Patent No. 2901228 discloses another laminating device in which a sheet material and a laminate film coated with a hot-melt adhesive are stacked together and inserted between a pair of rollers, at least one of which has a heating means installed therein, to heat and bond them together in one integral form, and in which an electric current to the heating means is cut off upon detecting an abnormal heating of the heating rollers by a heat detection means.
These devices, however, have drawbacks. In Japanese Patent No. 3779014, because the heating source such as an infrared heater and a planar heating source is used, a temperature control system (sensors and a temperature controller) for the heating source is required.
Also in Japanese Patent No. 2901228, a heating means such as a far-infrared tube heater is used, making it necessary to use a temperature control system. In addition, there is a possibility of the heating means going out of control during the heating operation. This requires some provisions to detect the abnormality.
The present invention has been accomplished to overcome the aforementioned problems. For this purpose, this invention aims at achieving a technology that allows for increasing a speed of a laminating temperature rise and maintaining the laminating temperature in a stable condition.